Method of making intaglio engravings



J 1955 F. LANDO 2,700,609 I METHOD OF MAKING INTAGLIO ENGRAVINGS Filed Dec. 16, 1953 COLORED ORIGINAL SEPARATION SEPARATION SEPARATION NEGAT VE NEGATIVE NEGATIVE I I I I I I I IUIIIINUflUS-TIJIIE HALF-TONE IIIITIIIIIIIIIs-TIIIIE HALF-TONE IIIIITIIIIIIIIIs-TIIIIE HALF-TONE DIAPOSITIVE DIAPOSITIVE DIAPOSITIVE DIAPOSITIVE DIAPOSI'I'IVE DIAPOSITIVE I I I I I I PRINT 0N PRINT 0N PRINT 0N CARBON TISSUE CARBON TIssuE CARBON TIssuE I I I ENGRAVING ENGRAVING ENGRAVING I I l i T i; T k PROOF FINISHING FINISHING FINISHING I I I l FINAL COLOR i I BLACK INK PRINT 0N BLACK INK PRINT 0N BLACK INK PRINT 0N TRANSLUCENT MATERIAL TRANSUJCENT MATERIAL TRANSLUCENT MA ERIAL I I I 2'2 PRINT 0N PRINT 0N PRINT ON 3 CARBON TISSUE CARBON TISSUE CARBON mm In (I) m I I I 5 L ENGRAvING ENGRAvING ENGRAVING 3r I \I COLOR PRINT I 1 INVENTOR.

Flu M640 BY 8%, T y I process, known. as.

2,700,609 METHOD on mmcuo 1121s.cnlwllss.s

55 .953; seems 3 8 539 aims (er-seen .evr isatisn 2m This .inventionrelatesto. a method of making intaglio ensrev ss's fi.me nai u e up i a ion o intaglio. engravings lwhi'chfh "e'be'en. corrected.

li i li tii -1 e dto color" p n s b en c n ct d by a 'ich consist in reretching I 7 ,thejcavities and burnishing parts; ofv the plate to, make the. c vities shallower. This mus im m sus ss .thaniattempts to c eCt' 1y ref chingthe transparencies used in making,tlie.res' tfqratheplate.

In printing ofadvertlsin'g matter which is to appear in a number. of. difierentpublications it-.is.desirahle.-to duplicate a correctef intagiio engraviiigto pr 'ovid'e'engravings which may be used: in-many dilferent printing plants without correcting. Prior to.. ny invention, there; has 5. .61 Q0 Inetiiodfor accurately dI heating a corrected i'ntaglide'ngraving". In accordance with my invention,

eepen parts of the. plate. m"

a I a. resist foretching a; duplicate of" a corrected intaglin engraving is. made by using an ink" prin t' tfro theengravingii direct association with a carbon tissueto co'ntrol the 'de'pths of the cavities in; thenew. engraving, while at. the same time making use of 'other means to m'akethe pattern'and area or the cavities correspond with those of the corrected engraving.

Intaglio engravings in which both the depth and the area of the cavities vary with the tones of the original are recognized as most desirable for printing and also as best adapted for correction by re-etching and burnishing. A special advantage of my invention is that it provides for making accurate duplicates of corrected intaglio engravings of this type.

To make the practice of my invention plain to those skilled in the art, I will describe in detail a specific method embodying it which is illustrated in the flow diagram of the accompanying drawing.

Color-separation negatives are made from a colored original, and from each negative a continuous-tone diapositive and a half-tone diapositive are made. The continuous-tone and half-tone 1 diapositives for each color are printed in succession on a carbon tissue, and copper plates are engraved from the developed carbon tissues in the usual manner. The plates are then corrected by socalled finishing which involves re-etching parts of them to increase the depth of the cavities in these parts and burnishing parts of them to reduce the depth of the cavities in these parts. Superimposed colored ink prints are made from the plates as the correcting progresses until the desired color effect has been obtained.

My method is applied to provide additional intaglio engravings accurately duplicating each of the color-corrected engravings. It involves the following steps with respect to the corrected engraving for each color:

An ink print is made from the corrected engraving on a transparent sheet. In this step, it is best to use black ink printed on a plastic sheet. To obtain good adherence, the ink should contain a solvent for the plastic. Printing on acetate sheets with an ink containing acetone is satisfactory.

An ink print from an intaglio engraving, unlike an ink print from a relief or letterpress engraving, does not reproduce the design in the plate from which it is printed. The design in an intaglio plate consists entirely of sep- 1 The half tones used in resists for intaglio engravings differ from those used in letterpress or relief engravmgs in that they have separated dots in their deepest tones like those in a middle tone of the half tones used in relief engravings.

'tain' ink from the shallowest cavities. of the ink varies diapositive wli'ichiwasused 2,700,609 Ratent'ed Jan. 25, 1955 h le P in f m su hap ats hs set ess s rea s into s lnt u us film Q so that the design of the cavities is ni r' d ch13 i. h i ht r as of hqpr nt whi h fin W; h .hefd irense .jy'd ease m'd rn pa y amassed r press Pa ern I a n S e t e me i an es e l in their areas, this 'transp ns i fi sh a b en: s We ca'te thereof;

A sa bent ssn signs-s din su ss iss to i h Ba e thrsus t e n aunt an li ht Pass n t 'dus t a -t -i-ilia ssi ve fa s-"a P 51- i en r sse made from the Idevelig' ed" tissue. This platecontairis cavities whose'pattern and areas correspond to the halftone diapositive-i he ink" print determines thedepth'of the cavities andhas: no effect on the pattern of the cavities except "in 'the' very light tones where the pattern of'the cavities has 'been re'served in. the ink" past. It is extretn'ely d ifiicult ntake this pattern exactly register with the-patterninthe,'lighttqnesproduced by the halft'one diapositive, and lackiof" register may lead to moir or: other objectionable effects.

have incorporated in my method, in its most desirable form, a step-formaking exact register unnecessary. This consists diffusing the pattern contained in" thelight areas of the ink print. Since thepa-ttcrn is contained only inthe light areas and is composed 'of yery thin dotsof ink, 'theusual' methods of'difiusing half'tone dots are not requiredi It is s ufiicient' topla'ce a: difiusingscreen eitherov'en or under the: ink print in the printin'g'fi'ame in which the carbon tissue is exposed to light through this print. The diffusing screen may consist of an acetate sheet having a ground surface, placed between the print and tissue.

In order to insure diffusion of the pattern in the light tones of the ink print, I have devised a new article. This is an acetate sheet ground on one surface and having an ink print from an intaglio plate on its smooth surface. When this article is placed in the printing frame with a carbon tissue, it insures an exposure similar to that obtained from a continuous-tone diapositive. The new article may be made by printing on other types of translucent sheets which have at least one smooth surface.

After the ink print, preferably with slight diffusion, and the half-tone diapositive have been printed on a carbon tissue, the tissue is stripped, reversed and washed in the usual manner and the new intaglio engraving is made by multiple etching through this resist.

A set of new intaglio color plates made by this method from color corrected intaglio engravings will be found to duplicate very closely the corrected engravings. Thus, color prints produced from the new set of plates differ in appearance very slightly, if at all, from the color print or proof obtained from the original engravings after the corrections had been completed.

It should be noted that, while the original corrected engravings may be made on fiat plates tofacilitate the making of corrections and the taking of proofs, the duplicate engravings may be made on cylindrically curved plates for application to printing cylinders. My method thus provides a method for making cylindrically curved intaglio engravings which duplicate corrected fiat intaglio engravings.

In the practice of my method, it is not essential that the half-tone diapositive used be the same diapositive which was used in making the original engraving. If preferred, a new half-tone diapositive may be made from the ink print by using a half-tone screen. This will have a dot pattern substantially the same as the cavity pattern of the corrected engraving.

It is not essential to my method that a carbon tissue be used as the resist for engraving the duplicate plates.

Other types of sensitive stripping tissues for intaglio resists, such as those containing silver salts, may be used instead of carbon tissue if preferred. The Words sensitive stripping tissue are used herein to comprehend such resist materials as Well as carbon tissue.

Besides providing the first means for duplicating corrected intaglio engravings, my method has the advantage of introducing an economy, as the intaglio ink prints on light-pervious sheets may be produced at much less ex-- pense than photographic diapositives.

What I claim is:

1. In the duplication of a corrected intaglio engraving which has been etched through a resist made by developing and stripping on a sensitive stripping tissue which as the result of two exposures contains a continuous-tone image and a half-tone image of the original, the method which comprises making an ink print from the corrected engraving on a light-pervious sheet and exposing a sensitive stripping tissue successively to the ink print and to a half-tone diapositive having opaque dots substantially corresponding in pattern and area with the pattern and area of the cavities of the corrected engraving, to provide a resist for the etching of a duplicate engraving.

2. In the duplication of a corrected intaglio engraving which has been etched through a resist made by developing and stripping on a sensitive stripping tissue which as the result of two exposures contains a continuous-tone image and a half-tone image of the original, the method which comprises making an ink print from the corrected engraving on a transparent sheet and exposing a sensitive stripping tissue successively (l) to the ink print and a difiiusing element and (2) to a half-tone diapositive having opaque dots substantially corresponding in pattern and area with the pattern and area of the cavities of the corrected engraving, to provide a resist for etching a duplicate engraving.

3. In the duplication of a corrected intaglio engraving which has been etched through a resist made by developing and stripping on a sensitive stripping tissue which as the result of two exposures contains a continuous-tone image and a half-tone image of the original, the method which comprises making an ink print from the corrected engraving on a translucent sheet and exposing a sensitive stripping 4 tissue successively to the ink print and to a half-tone diapositive having opaque dots substantially corresponding in pattern and area with the pattern and area of the cavities of the corrected engraving, to provide a resist for etching a duplicate engraving.

4. In the duplication of a corrected intaglio engraving which has been etched through a resist made by developing and stripping on a sensitive stripping tissue which as the result of two exposures contains a continuous-tone image and a half-tone image of the original, the method which comprises making an ink print from the corrected engraving on a light-pervious sheet, making a half-tone diapositive from the ink print by means of a half-tone screen, and exposing a sensitive stripping tissue successively to the ink print and to the half-tone diapositive, to provide a resist for the etching of a duplicate engraving.

5. The method of making duplicate corrected intaglio engravings, which comprises successively printing a continuous-tone diapositive and a half-tone diapositive on a sensitive stripping tissue, developing and stripping the tissue to form a resist, etching a metal plate through the resist to make" an intaglio engraving, correcting the plate, making an ink print from the corrected plate on a light-pervious sheet, exposing another sensitive stripping tissue successively to said ink print and to a half-tone diapositive having opaque dots substantially corresponding in pattern and area with the opaque dots of said halftone diapositive, developing and stripping said tissue to make a resist, and etching a second metal plate through said resist to make a duplicate engraving.

References Cited in the file of this patent UNITED STATES PATENTS 1,532,696 Hassard et a1. Apr. 7, 1925 1,577,181 Crowe Mar. 16, 1926 2,096,794 Dultgen Oct. 26, 1937 2,532,701 Falconer et al. Dec. 5, 1950 2,543,393 Wheldon Feb. 27, 1951 FOREIGN PATENTS 606,206 Great Britain Aug. 10, 1948 

1. IN THE DUPLICATION OF A CORRECTED INTAGLIO ENGRAVING WHICH HAS BEEN ETCHED THROUGH A RESIST MADE BY DEVELOPING AND STRIPPING ON A SENSITIVE STRIPPING TISSUE WHICH AS THE RESULT OF TWO EXPOSURES CONTAINS A CONTINUOUS-TONE IMAGE AND A HALF-TONE IMAGE OF THE ORIGINAL, THE METHOD WHICH COMPRISES MAKING AN INK PRINT FROM THE CORRECTED ENGRAVING ON A LIGHT-PERVIOUS SHEET AND EXPOSING A SENSITIVE STRIPPING TISSUE SUCCESSIVELY TO THE INK PRINT AND TO A HALF-TONE DIAPOSITIVE HAVING OPAQUE DOTS SUBSTANTIALLY CORRESPONDING IN PATTERN AND AREA WITH THE PATTERN AND AREA OF THE CAVITIES OF THE CORRECTED ENGRAVING, TO PROVIDE A RESIST FOR THE ETCHING OF A DUPLICATE ENGRAVING. 